package bp.tools;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class MD5Utill {

    public static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++){
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }


    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname)) {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
            }
        } catch (Exception exception) {
        }
        return resultString;
    }
    public static String MD52X_Encrypt(String origin ) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(origin.getBytes());
            byte[] digest = md.digest();
            StringBuilder sb = new StringBuilder();
            for (byte b : digest) {
                //16进制 不足2位前面补0
                sb.append(String.format("%02x", b));
            }
            return sb.toString().toUpperCase();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }


    private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    /**
     * md5加密
     * @param secretKey  秘钥
     * @param data       要加密的数据
     * @return
     */
    public static String HmacMd5Encode(String data,String secretKey) {
//            String secretKey = "your_secret_key"; // 秘钥
//            String data = "data_to_encrypt"; // 要加密的数据
            try {
                // 创建 HMAC-MD5 的 Mac 实例
                Mac mac = Mac.getInstance("HmacMD5");
                SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey.getBytes(), "HmacMD5");
                mac.init(secretKeySpec);
                // 进行加密
                byte[] hmacBytes = mac.doFinal(data.getBytes());
                // 将结果转换为 Base64 编码的字符串
                String hmacBase64 = Base64.getEncoder().encodeToString(hmacBytes);
                System.out.println("HMAC-MD5: " + hmacBase64);
                return hmacBase64;
            } catch (NoSuchAlgorithmException | InvalidKeyException e) {
                e.printStackTrace();
            }
            return "";
    }
    public static void main(String[] args) {
        String data="123";
        String secretKey="aaaa";
        String pwd1=HmacMd5Encode(data,secretKey);
//        System.out.println(pwd1); GAbQWfjkMfTEwyL6O0nj+w==
    }
}
